Executive Function as a Predictor of Instrumental Activities of Daily Living(IADLs) in Community-dwelling Older Adults

Abstract

Studies have supported that executive function is a more sensitive and stronger predictor of functional impairment than other cognitive abilities. Since improvements in executive function may bring about improved functional status, before developing an intervention, it is important to know what aspect of executive function is most closely related to functional status. Prior studies found three components of executive function; shifting, updating, and inhibition. The purpose of this study is to identify which component of executive function among updating, shifting, and inhibition is most closely related to functional abilities in older adults. 41 healthy community dwelling older adults aged from 66 to 90 years participated in this study. DAFS was used as a performance-based measure of instrumental activities of daily living (IADLs), including communication, financial, shopping, and medication tasks. A computerized battery of six executive function tasks was administered: Antisaccade and Stroop tasks tapping inhibition, Letter Memory and Keep Track tasks tapping updating, and Category Switch and Color Shape tasks tapping shifting. The results indicated that the measures of executive function predicted IADL functioning significantly. Measures of inhibition were the best predictors of ability to perform IADLs. This study suggests that inhibition may be important to perform IADLs, and the measures of inhibition might serve as a detector of initial functional decline among older adults.